Side wall sample taker



June 13, 1950 M. P. LE OURG SIDE WALL SAMPLE TAKER Filed June 1944 2 sheets heet 1 INVE TOR.

June 13, 1950 M. P. LEBOURG SIDE WALL SAMPLE TAKER 2 Sheets-Sheet 2 Filed June 9, 1944 M m a f m M N Patented June 13, 1950 SIDE WALL SAMPLE TAKER Maurice P. Lebourg, Houston, Tex, assignor to Schlumberger Well Surveying Corporation, Houston, Tex, a corporation of Delaware Application June 9, 1944, Serial No. 539,415

Claims. 3

This invention relates to devices for taking samples of the formations traversed by a bore hole, such as, for example, that produced in the drilling of an oil well or the like.

Many different types of devices have been developed heretofore for taking such samples from the side walls of a bore hole. Generally, the devices or tools have transverse recesses therein forming, in effect, a plurality of gun bores. A suitable hollow projectile is placed in eachgun bore and can be projected from the tool by a suitable propellant such as, for example, a charge of gun powder. Devices of the type referred to have certain disadvantages. The principal disadvantage is that the sample-taking projectiles are relatively small, and as a result are capable of receiving only a very small formation sample. Oftentimes the samples are too small to provide sulficient material for use in the laboratory in determining accurately the porosity, permeability and fluid content of the various formations. Moreover, when it is desired to obtain information regarding the microfauna inthe formation these small samples cannot always be depended upon as being representative of the formation.

There are several reasons for the restriction in the size of the projectile used in such sampletaking guns. In the first place, the diameter of the tool must be considerably less than the diameter of the bore hole. Usually the diameter of the sample taker gun body does not exceed four inches. Bore hole diameters generally range from six to ten inches.

In order to avoid supplying a wide variety of gun sizes, the bore hole apparatus is usually small enough to operate in the smallest size of bore hole generally encountered. For this reason, the diameter of the gun is about four inches.

The explosion pressures in the gun bore are very high and therefore considerable thickness of steel, usually not less than /2 inch, must be provided at the rear of the gun bore. In addition, space must be left for the powder itself, and as a result, the projectile cannot have an overall length greatly exceeding 2 /2 to 3 inches. The short length of the projectil cannot be. compensated for by making it of greater diameter forthe reason that the gun is cylindrical and an increase in'the diameter of the projectile necessitates a proportional decrease in the length of the projectile to maintain it within the peripheral limits of the gun.

An object of the present invention is to provide a gun type of sampling device which is capable of taking a larger sample of the side-wall formations of the bore hole than is possible with prior types of gun samplers.

Another object of the invention is to provide a sample-taking projectile that can penetrate the formations more easily and can be withdrawn from the formations with less difficulty than prior types of sampling projectiles.

Another object of the invention is to provide a novel form of explosive charge or cartridge that facilitates the use of larger sample-taking projectiles than could be used heretofore.

Other objects of the invention will become apparent from. the following description of typical forms of the sampling guns, projectiles and explosive charges embodying the invention.

In accordance with the present invention, I have provided a sample-taking tool or gun with a powder chamber which is disposed between the ends of the sample-taking projectile and at least partially surrounds the projectile. The pressure derived fromthe explosive charge is applied to a shoulder formed on the periphery of the projectile rather than to the end of the projectile.

More particularly, the bore or aperture for receiving the projectile may extend completely through the tool and the bore and projectile are so constructed as to provide opposed shoulders defining an annular space or chamber for receiving the explosive charge.

Inasmuch as the bore-of the gun is open at both ends, a retrieving means such as a cable or a spring may be attached to the rear end of the projectile. By connecting the retrieving means to the rear end of the projectile, the outside diameter of the forward end of the projectile is reduced and the projectile can penetrate into the formation more readily or a smaller explosive charge may be used to produce the desired penetration.

This type of sample-taking tool has the advantage that a sample-taking projectile may be used therein that is substantially as long as the diameter of the sample-taking gun and thus is capable of taking a sample 50 to larger than is. possible with the projectiles used in sample-taking guns of the same external dimensions.

For a better understanding of the present invention, reference may be had to the accompanying drawings in which:

Figure 1 is a side view of a typical form of'sample-taking device embodying the present invention;

Figure 2 is a view insection taken in line 2-2 of Figure 1;

Figure 3 is a view in section taken on line 3-3 of Figure 2;

Figure 4 is a perspective View of a typical form of explosive charge unit or cartridge used in the sample-taking device;

Figure 5 is a view in cross-section through the device showing a modified type of projectile for the device, and

Figure 6 is a view in cross-section through the device illustrating another type of projectile for the gun.

The sample-taking device illustrated in Fi ures l and 2 of the drawings includes a cap member it provided with an internally threaded recess I911 which is secured to a tool or gun body II of generally cylindrical shape and of a size adapted to fit within a bore hole. The tool body II is provided with an externally threaded portion I la which is adapted to be threaded into the cap member Ill. The lower end of the body II is provided with an internally threaded recess II?) which is complemental to the externally threaded portion I la and thereby permits a series of such tool bodies I I to be connected end to end. As illustrated, the lower end of the tool body II may be provided with a bullet-nosed portion I2 which is threaded into the recess I lb.

The above-described assembly or a plurality of the tool bodies II may be lowered into or with drawn from a bore hole by means of a cable I3 which is provided with one or more electrical conductors I I.

As shown particularly in Figures 2 and 3, the body I I of the tool is provided with a plurality of transverse apertures I5a, I51), I50 and I5d extending completely therethrough forming gun bores for receiving sample-taking projectiles. The aperture I50, as illustrated in Figure l, faces in such a direction that the projectile therein will be discharged in the same direction as the projectile in the aperture I5a. The apertures I51) and I5d are faced in the opposite direction so that the projectiles therein are projected from the opposite side of the gun body II. Inasmuch as all of the apertures I5a to I 5d are essentially the same, only one of these apertures will be described herein. The aperture I5b is provided with a portion I6 of smaller diameter, a larger diameter portion I! and an intermediate shoulder I8. One type of sampling device suitable for use in the tool may consist of a tubular projectile I9 having a reduced cylindrical outer surface portion I9a fitting the portion I6 of the aperture. The forward end I91) of the projectile is tapered inwardly from a shoulder portion I90 extending circumferentially of the projectile at substantially a right angle to the axis of the projectile.

The projectile I9 also carries a detachable ring I9d of substantially L-shaped cross-section which is adapted to abut against the shoulder I90, overlie a portion of the tapered surface 1% and. fit closely against the wall of the aperture portion When the projectile I9 is substantially centered in the gun body II, an annular space for reception of an explosive charge device or cartridge 29 is left between the ring IM and the shoulder I8 and between the enlarged diameter portion I! and the reduced cylindrical portion I9a of the I projectile I9.

4 thetic plastic or other thin destructible material. This casing is adapted to be partially or completely filled with a suitable explosive such as gun powder. Also disposed within the chamber and in contact with the explosive is an ignition filament 2I which is connected to suitable contacts 22 and 22a that are exposed externally of the casing 29a. The diameter of the filament or the material of which the filament is formed may vary and preferably the filaments of different cartridges will require currents of different values to cause the filaments to glow.

In order to retrieve the projectiles I9 after they have been driven into the side wall of the bore hole, the projectiles may be connected to the sample-tool body II by means of a suitable flexible member such as for example, the cable 23, illustrated in Figures 1, 2 .and 3. The projectile I9 may be provided with a cross piece 24 which is pivotally connected to the rear portion of the projectile by means of a pair of stud shafts 25 and 26 threaded through the wall of projectile I9 as shown in Figure 3. One end of the cable 23 is connected to the cross piece in any suitable way and may be coiled in a recess 2! concentric with the aperture I5. The opposite end of the cable 23 may be provided with a lug 28 that is detachably fastened'to the tool body I I.

The opposite end of the gun bore or aperture I5 may also be enlarged in order to facilitate insertion of the cartridge 20 and the projectile I9.

In order to actuate the gun from the surface of the earth, the conductor I4 may be led into the cap I!) and connected to a pin 30 which is insulated from the cap and. is received in an insulating bushing 3I in the upper end of the body I I. The pin 30 makes contact with another conducting pin 32 that is carried in the upper end of the body I I and is insulated therefrom by a suitable bushing 33. The lower end of the pin 32 is adapted to engage one of the contacts 22 or 22a of the cartridge 20. The other contact of the cartridge is adapted to engage another pin 34 that is insulated from the gun body by a suitable insulating bushing 35, this latter pin engaging a contact of the next lower explosive charge device 20. Similar insulated contact pins 36 and 31 are provided along the axis of the body II depending upon the number of powder chambers therein. At the lower end of the body II is disposed an elongated pin 38 which is insulated from the body II and can make contact with a spring contact 39 in the bullet-nosed end I2 of the device or with a contact pin, such as the pin 32, of another sample-taking tool.

When the gun body is very long, drilling the axial holes for insulating bushing 35 may become a tedious operation. In this case, it is sometimes advisable to make the electrical connection between adjacent powder cartridges by passing insulated conductors through holes drilled transversely of the body, making the electrical connections on the periphery of the gun body.

Inasmuch as the bullet-nosed end I2 is in contact with the conductive liquid in the bore hole, a circuit through the various filaments 2I of the cartridges can be completed by grounding one pole of a source of electrical energy or connecting it to a conducting sheath on the cable I3 and connecting the other pole to the conductor I4.

Preferably, the filaments 2I of the cartridges 29 required different current values to cause them to glow. Therefore, by applying a current to the series of charges which is suflicient only to cause the lowermost filament to glow, only the lowermost powder charge is caused to explode. After the gun has been fired, the conductive fluid in the bore hole will rush into the aperture I5d, for example, again completing the circuit and permitting the next higher powder charge to be exploded by application of a greater current thereto.

The tool may be prepared for use by placing the cartridge 29 in the aperture I5a. The projectile [9 with a ring l9d thereon is then inserted into the aperture l1 and a sealing ring 40 formed'of rubber or neoprene pushed into the space between the tapered portion I92) and the wall of the enlarged aperture [1 to prevent liquid from coming into contact with the powder charge. Also, a second sealing ring may be disposed in a groove M in the reduced diameter portion of the aperture iii to prevent leakage of the bore hole liquid around the projectile [9. The cable 23 is then coiled around the end of the projectile l9 and secured to the gun body I I, as described above. This procedure is repeated until all of the bores, or as many thereof as desired, are loaded. The whole assembl may then be lowered into the bore hole so that the lowest gun bore or aperture d is adjacent the formation of interest. The location of this formation can be determined in any suitable way such as, for example, by means of the method disclosed in the Schlumberger Patent No. Re. 20,120.

A current of sufficiently high value is then impressed upon the filament 2| of the cartridges to cause the filament in the lowermost cartridge to glow, igniting the powder and causing the projectile [9 to be discharged into the, formation. The tool may then be raised and the next higher projectile discharged into another formation of interest.

The retrieving cable 23 in each instance will exert a strain on the projectile as the tool is moved along the bore hole and will withdraw the projectile from the formation together with a sample of the formation therein.

It has been found that difierent types of formations require diiferent types of projectiles for taking a sample therefrom. Different types of projectiles, therefore, may be provided for use in a device of the type described above.

As shown in Figure 5, for example, a projectile :35 of tubular formation may be used which has an enlarged diameter flange portion 35a thereon fitting the enlarged diameter portion H of the aperture. The function of the enlarged flange 45a is similar to the function of smaller shoulder 81) and the ring sea illustrated in Figures 2 and 3, namely, to provide a shoulder against which the explosion pressure can act to propel the projectile. The forward end portion 45b of the projectile G5 is tapered to facilitate its penetration into the formation.

A modified form of projectile is shown in Figure 6. This rojectile 36 includes a smaller diameter tubular portion fia and a larger diameter portion 629 and an abruptly tapered forward portion 380. The large diameter portion 46b fits the interior of the large diameter portion ll of the aperture. Inasmuch as this type of projectile would tend to be retained tightly in a formation, the leading end of the projectile is provided with a cap 4? formed of sheet metal or the like which corresponds in shape to the leading end of the projectile and has a flange 41a encircling and disposed outside the periphery of the projectile.

The cap 41 is frangible to permit the entry of the sample.

When this type of projectile is fired into the formation, the diameter of the hole produced corresponds to the outside diameter of the cap 41a, and thus is larger than the largest diameter of the projectile 46 When a strain is exerted on the projectile 46 tending to withdraw it from the formation, the projectile is freed from the cap 31 and can be withdrawn readily from the formation leaving the cap 41 in the formation.

It will be understood, of course, that the projectiles can be modified considerably, as for example, by providing a closure or a partial closure for the rear end of the projectile in order to prevent the sample from being washed from the projectile during its withdrawal from the bore hole. The projectiles may be corrugated internally or provided with core catching devices, the construction and use of which are well known in the art.

The electrical connections between the igniting filaments of the explosive charge 20 need not be made along the axis of the gun body II. If desired, the electrical connections can be made by means of insulated conductors extending along the side of the gun body and connected to suitable terminals on the sides of the gun body. The contacts 22 and 22a on the explosive charge may be positioned wherever convenient for making such connections.

When a plurality of the sample-taking. devices are connected in series, it may be desirable to provide separate firing conductors for each sample-t'aking device or for groups of one or more of the sample-taking devices. Such multiple connections may be necessary for the reason that there, is a practical limit to the number of igniting filaments that. may be successfully operated when connected in series. Thus, instead of connecting a great number of filaments in series, one conductor may be used to fire 8 or 10 projectiles, another conductor may be used to fire still another group nd so on.

From the above description it will be apparent that a device has been provided which is capable of being operated to take larger samples of the formations traversed by a bore hole without increase in over-all size of the sample-taking device. Moreover, the device is highly flexible in use, permitting any desired number of samples to be taken during a traverse of the bore hole. In addition, it will be understood that the device may be provided with various types of projectiles depending upon the types of formation from which samples are to be taken and the device may be modified insofar as the firing circuits and the size. and dimensions of the parts of the device are concerned without departing from the invention. Therefore, the form of the invention described above should be considered as illustrative and not as limiting the scope of the following claims.

I claim:

1. A device for taking samples of the formations traversed by a bore hole comprising a gun body having an aperture extending completely transversely therethrough adapted to be lowered into a bore hole, a hollow sample-taking projectilein said aperture and of substantially the same length as said aperture, and cooperating means on said gun body and on said projectile forming a chamber between the ends of said aperture for receiving an explosive charge and providing an acting. surface onthe; projectile for said explosive charge for propelling said projectile from said aperture.

2. A device for taking samples of the formations traversed by a bore hole comprising a gun body having an aperture extending completely transversely therethrough adapted to be lowered into a bore hole, a hollow sample-taking projectile in said aperture and of substantially the same length as said aperture, means forming a chamber between the ends of said aperture for receiving an explosive charge for propelling said projectile from said aperture, said last named means including an acting surface on the projectile for said explosive charge, and an elongated flexible member connected to the gun body and the rear end of said projectile.

3. A device for taking samples of the formations traversed by a bore hole comprising a gun .body adapted to be lowered into a bore hole having an aperture extending completely transversely therethrough, a hollow sample-taking projectile in said aperture and of substantially the same length as said aperture, and cooperating means in said aperture and on said projectile, between their ends forming a chamber at least partially encircling said projectile for receiving an explosive charge, and providing an acting surface on the projectile for said explosive charge whereby the projectile may be propelled from the gun body.

4. A device for taking samples of the formations traversed by a bore hole comprising a gun body adapted to be lowered intoa bore hole having an aperture extending completely transversely therethrough, a hollow sample-taking projectile in said aperture and of substantially the same length as said aperture, and cooperating means in said'aperture and on said projectile, between their ends forming an annular chamber for receiving an explosive charge, and providing an acting surface on the projectile for said explosive charge whereby the projectile may be propelled from the gun body.

' 5. A device for taking samples of formations traversed by a bore hole, comprising a gun body adapted to be lowered into a bore hole, means forming an aperture extending completely transversely through said gun body, said aperture having a rear portion of one diameter and a front portion of larger diameter with a shoulder therebetween, a hollow projectile of substantially the same length as said aperture received within said aperture and having a rear portion fitting the rear portion of said aperture, and means on said projectile disposed within the larger diameter portion of said aperture, said shoulder and said means on said projectile being spaced apart to provide a chamber therebetween for receiving an explosive charge, and providing an acting surface on the projectile for said explosive charge whereby the projectile may be propelled from the gun body.

6. A device for taking samples of the formations traversed by a bore hole comprising a gun body adapted to be lowered into a bore hole, means forming at least one aperture extending completely transversely through said body, said aperture having a smaller diameter portion and a larger diameter portion separated by a shoulder, a tubular sample-taking projectile of substantially the same length as said aperture .receivable in said aperture having a portion fitting said smaller diameter portion, and means carried by said projectile disposed within said larger diameter portion andforming with said shoulder and a portion of said larger diameter portion a chamber for receiving an explosive charge, said last named means providing an acting surface on the projectile for said explosive charge Whereby the projectile maybe propelled from the gun body.

7. A device for taking samples of formations traversed by a bore hole comprising a gun body having an aperture extending completely transversely therethrough, a hollow' sample-taking projectile in said aperture and of substantially the same length as the aperture, means in said gun body and on-said projectile forming a chamber for receiving an explosive, at least partially encircling said projectile and providing and acting. surface on the projectile for said explosive charge whereby the projectile maybe propelled from the gun body, and a flexible member for connecting the rear end of said projectile to said gun body.

8. A device for taking samples of formations traversed by a bore hole, comprising a gun body adapted to be lowered into a bore hole, means forming an aperture in said body extending completely transversely therethrough and having a smaller diameter portion, a larger diameter portion and a shoulder therebetween, a projectile of substantially the same length as said aperture fitting in said aperture and having a radially extending shoulder between its ends, said shoulders being normally spaced apart when the projectile is inserted in said aperture to provide a chamber therebetween for receiving an explosive charge.

9. The device set forth in claim 8, in which the gun body is provided with a plurality of substantially parallel apertures in alternately reversed positions.

, 10. A device for taking samples of formations traversed by a bore hole, comprising a gun body adapted to be lowered into a bore hole, means forming an aperture in said body extending completely transversely therethrough and having a smaller diameter portion, a larger diameter portion and a shoulder therebetween, a projectile of substantially the same length as said aperture fitting in said aperture and having a radially extending shoulder between its ends, said shoulders being normally spaced apart when the projectile is inserted in said aperture to provide a chamber therebetween for receiving an explosive charge, and a flexible elongated member having one end secured to said gun body and the other end secured to the rear end of said projectile.

MAURICE P. LEBOURG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 53,582 De Coursey Apr. 3, 1866 2,048,451 Johnston July 21, 1936 2,055,506 Schlumberger Sept. 29, 1936 2,119,361 Schlumberger May 31, 1938 2,149,814 Littlehale Mar. 7, 1939 2,276,161 Cole Mar. 10, 1942 2,281,870 Cole May 5, 1942 2,288,210 'Schlumberger June 30, 1942 2,324,551 Albree July 20, 1943 FOREIGN PATENTS Number Country Date 216 Great Britain 1861 74,758 Switzerland Jan. 16, 1919 

